North Haverhill — Prosecutors plan to drop a rape charge against a Lyme man who spent two years in prison before his conviction was overturned last year.

William K. Town, 37, was scheduled to stand trial in April for the fourth time on allegations that he sexually assaulted two girls at his mother’s day care center in Hanover in the 1990s.

In a court filing this week, Grafton County Attorney Lara Saffo announced that she was dropping the case against Town, ending a six-year legal saga.

“The reaction is one of relief,” defense attorney George Ostler said. “It’s been six to seven years for Mr. Town. We’re just glad it’s come to an end. We can’t go back and change any of that.”

Town did not respond to a message seeking comment yesterday.

Saffo said she plans to drop the case — which could happen as early as Monday — because Town’s accuser has “determined it is not in her family’s best interest to endure a third trial.”

“The State respects the victim’s decision and is not going to force her to testify,” Saffo wrote in a document announcing her decision. “The State appreciates her willingness to participate in the criminal justice system to date, and wishes her the best. “

Town, who is married with two children and two stepchildren, came to attention of authorities in 2007, when two women went to Hanover police and alleged that Town raped them while they attended his mother’s unlicensed day care center in Hanover the previous decade.

Town, who previously lived in Norwich, has been tried three times. He was acquitted in 2009 of charges related to one of the assaults. In 2010, a jury deadlocked at the trial on charges related to the other accuser. At the retrial later that year, Town was convicted and sentenced to prison. Last summer, the New Hampshire Supreme Court overturned that conviction because of concerns about the impartiality of one of the jurors.

Ostler said even with the prosecution dropping the case, Town will find it difficult to overcome the stigma associated with the charges and the overturned conviction, which generated significant publicity.

“In the Internet age, that’s a good question,” Ostler said. “Our society isn’t very good as far as allowing a person to rehabilitate themselves after going through this.”

Town’s wife, Cathy, remained with him throughout the trials and his incarceration.

The complainant, a mother in her early 30s who still lives in the Upper Valley, could not be reached for comment yesterday. Saffo said the woman “found the criminal justice process to be unfair to victims and she no longer has faith that the criminal justice system will process the case without further errors.”

As a general practice, the Valley News does not identify victims of sex crimes. The woman had told authorities the assault occurred in Hanover between 1990 and 1992, when she was between 11 and 14 years old, and Town was between 15 and 17.

Weeks ago, Town’s defense team filed a motion requesting copies of the accuser’s medical and psychiatric records. Saffo formally opposed the request, and said the woman had decided that she did not want to proceed with the case before learning the motion was filed.

The decision to drop the prosecution marks a dramatic turnabout for the Grafton County Attorney’s Office, which has vigorously pursued Town. Even after the state Supreme Court overturned his conviction, Saffo fought Town’s release from prison last summer, and asked a judge to hold him without bail while awaiting a retrial. (Town had previously been released on bail while awaiting his earlier trials.)

The judge eventually freed Town pending next month’s trial.

Hanover Police Capt. Frank Moran, the lead investigator in the case, declined to comment yesterday.

In September 2009, a jury found Town not guilty of assaulting one of the women, who alleged that Town assaulted her between 1996 and 1999.

Though the facts and evidence were similar, prosecutors proceeded to try Town on the other women’s complaint. That trial, in June 2010, resulted in a hung jury and a mistrial. Three months later, prosecutors tried again. At that trial, jurors twice told a judge that they were deadlocked, but eventually issued a guilty verdict. Town, who had been living in the community with his family, was sent to prison.

He remained there for two years. Last July, the state Supreme Court unanimously overturned his conviction, saying that one of the jurors was not impartial — she had told the judge that she was once sexually abused and said she was “not sure” if she could disregard her personal experiences while evaluating the evidence.

Yesterday, Saffo noted that the high court’s decision to overturn was not based on any perceived problems with the prosecution’s case.

Ostler and fellow defense attorney Wayne Young, of Norwich, had planned to ask a judge to dismiss the case, arguing that prosecutors had violated Town’s due process rights by repeatedly putting him on trial for the same allegations.

The defense attorneys were focusing on factors that have complicated the case from the beginning. The allegations were nearly 20 years old, there were no witnesses or physical evidence, and the women could not remember exactly when the alleged incidents occurred.

In seeking access to the accuser’s medical or mental health records, defense attorneys said they intended “to demonstrate on cross-examination that (the victim’s) accusations are unreliable and medically questionable,” according to court filings.